A common type of railroad freight car in use today is an open top hopper car wherein the commodity carried by the railcar is discharged through openings provided on an underside of the car. Such railcars are used to haul aggregate, iron ore, coal and other commodities. Such railcars offer an advantageously economical method of transporting large amounts of such commodity between distantly spaced locations.
Such railcars typically include a walled enclosure or hopper carried by an underframe of the railcar. On some railcars, the underframe includes a longitudinally elongated centersill or support which is mounted, toward opposite ends thereof, by conventional wheeled trucks which ride on tracks or rails. Although the design of railcar hopper varies considerably between manufacturers, the railcar hopper is typically provided with a plurality of longitudinally spaced chutes. Each chute has discharge openings through which commodity is exhausted from the car. The discharge openings on a hopper type railcar extend either parallel to the longitudinal axis of the railcar (longitudinal openings) or are disposed in generally aligned pairs on opposite lateral sides of the longitudinal axis of the railcar (transverse openings). Each type hopper serves a particular need in the railcar industry.
To control the discharge of commodity from the railcar hopper, a door is arranged in operable combination and preferably in registry with each discharge opening on the railcar hopper. Basically, each door is hinged along an upper edge such that, when released, the door gravitationally swings toward an open position assisted by the commodity gravitationally moving through the discharge opening.
As will be appreciated, different door operating mechanisms have been proposed to move the doors between their closed and open positions. Preferably, the door operating mechanism will also serve to positively maintain the doors in their closed position during transport of the railcar between distantly spaced locations. It is important to note, however, such door operating mechanisms are specifically designed to the particular application with which they find use. For example, a mechanism used to operate longitudinally mounted doors cannot, without substantial redesign, be used to operate transversely aligned doors. For this and other reasons, those mechanisms used to operate longitudinally mounted doors do not and are not readily useful with those hopper cars having transversely mounted doors.
Designing an apparatus for operating transversely mounted doors on a hopper car involves serious design challenges. Manually operated devices for releasably holding transversely aligned doors in a closed position are known in the art. One such device involves using hooks or catches in combination with each door. Such prior art designs, however, typically require a person on each side of the railcar to release the hook or catch whereby allowing the door to swing toward an open position. Because of the location of the doors relative to the railcar hopper, however, access to such hook or catch is limited. Moreover, having a person on each side of the railcar to release the locks or catches from operable engagement with the doors is costly and, thus, adverse to the railcar industry. It has also been proposed to join or couple the two doors on opposed sides of the car to each other. Such design, however, does not necessarily reduce the persons required to release the doors from their closed and locked positions.
Other manually operated designs for opening and closing transversely mounted doors on a railroad road hopper car are also known in the art. One such manually operated door operating design involves mounting an elongated operating shaft on the underframe of the railcar for rotation about a fixed axis and a linkage system for operably interconnecting the operating shaft with the two transversely aligned doors mounted on the hopper of the railcar. While having several advantageous characteristics, this prior art design requires manual operation from either side of the railcar. As mentioned with respect to the manually operated locks or catches discussed above, having a person on each side of the railcar to operate the door operating mechanism is costly and, thus, adverse to the railcar industry.
It would be advantageous, therefore, to design a power operated door operating mechanism including a lock for holding the doors in their closed position. If the power operated mechanism is operated before the lock is released, however, considerable damage to a driver for such mechanism, the linkage operably associated with such mechanism, and etc. can occur, thus, severely complicating the overall design of such a mechanism.
With any power operated door operating device there is considerable concern over what could happen if there is a loss of power, for any reason, to such door operated device. That is, and after the hopper car arrives at an unloading site, what happens if there is no source of power for operating a powered door operating mechanism? Additionally, and after the hopper car arrives at an unloading site, what happens if power to an otherwise powered door operated mechanism is temporarily lost? As will be appreciated by those skilled in the art, most hopper car unloading sites allow only a minimum of time for the railcar to be unloaded and moved through the unloading site. If, for whatever reason, the power operated mechanism fails to successfully operate the discharge doors, the fully loaded railroad hopper car simply must be returned to the original location. The adverse costs of having to return a fully loaded car because the power operated mechanism failed to open the discharge doors is apparent.
Unless the doors on the hopper are fully closed during the entire travel of the railcar between locations, there can be a considerable loss of commodity from the hopper. As will be appreciated by those skilled in the art, it is difficult—at best—to determine whether the discharge doors on the hopper are fully closed simply by viewing the doors from the side of the hopper car. Accordingly, a relatively large number of loaded railroad freight cars are inadvertently added to a train consist with the doors being either partially open or with a lock assembly not being fully engaged with the door assembly. As a result, some such cars irretrievably lose relatively large quantities of commodity as they are transported between distant locations.
Thus, there is a need and continuing desire for a power operated apparatus designed to operate a pair of transversely mounted discharge doors on a railroad hopper car and wherein the power operated apparatus includes a lock which is operated in timed sequence to movement of the doors and which permits manual operation, when required, to affect release of the lock and, thus, timely discharge of commodity from the railcar and which furthermore includes an apparatus for visually indicating, from at least one side of the railcar, the operable condition of the door assembly lock.